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Friday, April 3, 2009

Virus battery could 'power cars'

Viruses have been used to help build batteries that may one day power cars and all types of electronic devices.

The speed and relatively cheap cost of manufacturing virus batteries could prove attractive to industry.

Professor Angela Belcher, who led the research team, said: "Our material is powerful enough to be able to be used in a car battery."

The team from MIT in the US is now working on higher power batteries. ...

The virus is a so-called common bacteriophage which infects bacteria and is harmless to humans. Three years ago the MIT scientists manipulated genes inside a virus that coaxed the particles to grow and self-assemble to form a nanowire anode one-tenth the width of a human hair.

The microbes are encouraged to collect exotic materials - cobalt oxide and gold - and because the particles are negatively charged, they can be formed into a dense, virus-loaded film which acts as an anode and "grows" on a polymer separator.

Researchers, including MIT Professor Gerbrand Ceder and Associate Professor Michael Strano, have now developed a highly powerful cathode. The work was more difficult because the material had to be highly conductive in order to be effective and most candidate materials for cathodes are highly insulating.

... The virus was coaxed into binding with iron phosphate and then carbon nanotubes to create a highly conductive material.

The batteries have the same energy capacity and power performance as rechargeable batteries used to power plug-in hybrid cars.

The prototype battery is currently the size of a coin but the scientists believe it can be scaled and be used to create flexible batteries that can take the shape of their container, which is perfect for mobile or small devices.

The scientists have also been able to create micro-batteries which could be used to power a future generation of tiny devices.

"The advantage of using genetics is that things can be made better and better," explained Professor Belcher.